This tutorial shows you how to use Eventarc to build a processing pipeline that schedules queries to a public BigQuery dataset, generates charts based on the data, and shares links to the charts through email.
Objectives
In this tutorial, you will build and deploy three Cloud Run services that allow unauthenticated access and that receive events using Eventarc:
- Query Runner—Triggered when Cloud Scheduler jobs publish a message to a Pub/Sub topic, this service uses the BigQuery API to retrieve data from a public COVID-19 dataset, and saves the results in a new BigQuery table.
- Chart Creator—Triggered when the Query Runner service publishes a message to a Pub/Sub topic, this service generates charts using the Python plotting library, Matplotlib, and saves the charts to a Cloud Storage bucket.
- Notifier—Triggered by audit logs when the Chart Creator service stores a chart in a Cloud Storage bucket, this service uses the email service, SendGrid, to send links to the charts to an email address.
The following diagram shows the high-level architecture:
Costs
In this document, you use the following billable components of Google Cloud:
To generate a cost estimate based on your projected usage,
use the pricing calculator.
Before you begin
Security constraints defined by your organization might prevent you from completing the following steps. For troubleshooting information, see Develop applications in a constrained Google Cloud environment.
- Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
-
In the Google Cloud console, on the project selector page, select or create a Google Cloud project.
-
Make sure that billing is enabled for your Google Cloud project.
-
Enable the Cloud Build, Cloud Logging, Cloud Run, Cloud Scheduler, Container Registry, Eventarc, Pub/Sub APIs.
- Install the Google Cloud CLI.
-
To initialize the gcloud CLI, run the following command:
gcloud init
-
In the Google Cloud console, on the project selector page, select or create a Google Cloud project.
-
Make sure that billing is enabled for your Google Cloud project.
-
Enable the Cloud Build, Cloud Logging, Cloud Run, Cloud Scheduler, Container Registry, Eventarc, Pub/Sub APIs.
- Install the Google Cloud CLI.
-
To initialize the gcloud CLI, run the following command:
gcloud init
- Update gcloud components:
gcloud components update
- Log in using your account:
gcloud auth login
- Select Google Cloud Storage and enable the Admin Read, Data Read, and Data Write Log Types:
- Grant the
eventarc.eventReceiver
role to the Compute Engine service account:export PROJECT_NUMBER="$(gcloud projects describe $(gcloud config get-value project) --format='value(projectNumber)')" gcloud projects add-iam-policy-binding $(gcloud config get-value project) \ --member=serviceAccount:${PROJECT_NUMBER}-compute@developer.gserviceaccount.com \ --role='roles/eventarc.eventReceiver'
- If you enabled the Pub/Sub service account on or before April 8,
2021, grant the
iam.serviceAccountTokenCreator
role to the Pub/Sub service account:gcloud projects add-iam-policy-binding $(gcloud config get-value project) \ --member="serviceAccount:service-${PROJECT_NUMBER}@gcp-sa-pubsub.iam.gserviceaccount.com"\ --role='roles/iam.serviceAccountTokenCreator'
- Set the defaults used in this tutorial:
export REGION=REGION gcloud config set run/region ${REGION} gcloud config set run/platform managed gcloud config set eventarc/location ${REGION}
Replace REGION with the supported Eventarc location of your choice.
- Download and install the Git source code management tool.
Create a SendGrid API key
SendGrid is a cloud-based email provider that lets you send email without having to maintain email servers.
- Sign in to SendGrid and go to Settings > API Keys.
- Click Create API Key.
- Select the permissions for the key. At a minimum, the key must have Mail Send permissions to send email.
- Click Save to create the key.
- SendGrid generates a new key. This is the only copy of the key, so make sure that you copy the key and save it for later.
Create a Cloud Storage bucket
Create a unique Cloud Storage bucket to save the charts. Make sure that the bucket and the charts are publicly available, and in the same region as your Cloud Run service:
export BUCKET="$(gcloud config get-value core/project)-charts" gsutil mb -l $(gcloud config get-value run/region) gs://${BUCKET} gsutil uniformbucketlevelaccess set on gs://${BUCKET} gsutil iam ch allUsers:objectViewer gs://${BUCKET}
Deploy the Notifier service
Deploy a Cloud Run service that receives Chart Creator events and uses SendGrid to email links to the generated charts.
Clone the GitHub repository and change to the
notifier/python
directory:git clone https://github.com/GoogleCloudPlatform/eventarc-samples cd eventarc-samples/processing-pipelines/bigquery/notifier/python/
Build and push the container image:
export SERVICE_NAME=notifier docker build -t gcr.io/$(gcloud config get-value project)/${SERVICE_NAME}:v1 . docker push gcr.io/$(gcloud config get-value project)/${SERVICE_NAME}:v1
Deploy the container image to Cloud Run, passing in an address to send emails to, and the SendGrid API key:
export TO_EMAILS=EMAIL_ADDRESS export SENDGRID_API_KEY=YOUR_SENDGRID_API_KEY gcloud run deploy ${SERVICE_NAME} \ --image gcr.io/$(gcloud config get-value project)/${SERVICE_NAME}:v1 \ --update-env-vars TO_EMAILS=${TO_EMAILS},SENDGRID_API_KEY=${SENDGRID_API_KEY},BUCKET=${BUCKET} \ --allow-unauthenticated
Replace the following:
- EMAIL_ADDRESS with an email address to send the links to the generated charts
- YOUR_SENDGRID_API_KEY with the SendGrid API key you noted previously
When you see the service URL, the deployment is complete.
Create a trigger for the Notifier service
The Eventarc trigger for the Notifier service deployed on
Cloud Run filters for Cloud Storage audit logs where
the methodName is storage.objects.create
.
Create the trigger:
gcloud eventarc triggers create trigger-${SERVICE_NAME} \ --destination-run-service=${SERVICE_NAME} \ --destination-run-region=${REGION} \ --event-filters="type=google.cloud.audit.log.v1.written" \ --event-filters="serviceName=storage.googleapis.com" \ --event-filters="methodName=storage.objects.create" \ --service-account=${PROJECT_NUMBER}-compute@developer.gserviceaccount.com
This creates a trigger called
trigger-notifier
.
Deploy the Chart Creator service
Deploy a Cloud Run service that receives Query Runner events, retrieves data from a BigQuery table for a specific country, and then generates a chart, using Matplotlib, from the data. The chart is uploaded to a Cloud Storage bucket.
Change to the
chart-creator/python
directory:cd ../../chart-creator/python
Build and push the container image:
export SERVICE_NAME=chart-creator docker build -t gcr.io/$(gcloud config get-value project)/${SERVICE_NAME}:v1 . docker push gcr.io/$(gcloud config get-value project)/${SERVICE_NAME}:v1
Deploy the container image to Cloud Run, passing in
BUCKET
:gcloud run deploy ${SERVICE_NAME} \ --image gcr.io/$(gcloud config get-value project)/${SERVICE_NAME}:v1 \ --update-env-vars BUCKET=${BUCKET} \ --allow-unauthenticated
When you see the service URL, the deployment is complete.
Create a trigger for the Chart Creator service
The Eventarc trigger for the Chart Creator service deployed on Cloud Run filters for messages published to a Pub/Sub topic.
Create the trigger:
gcloud eventarc triggers create trigger-${SERVICE_NAME} \ --destination-run-service=${SERVICE_NAME} \ --destination-run-region=${REGION} \ --event-filters="type=google.cloud.pubsub.topic.v1.messagePublished"
This creates a trigger called
trigger-chart-creator
.Set the Pub/Sub topic environment variable.
export TOPIC_QUERY_COMPLETED=$(basename $(gcloud eventarc triggers describe trigger-${SERVICE_NAME} --format='value(transport.pubsub.topic)'))
Deploy the Query Runner service
Deploy a Cloud Run service that receives Cloud Scheduler events, retrieves data from a public COVID-19 dataset, and saves the results in a new BigQuery table.
Change to the
processing-pipelines
directory:cd ../../..
Build and push the container image:
export SERVICE_NAME=query-runner docker build -t gcr.io/$(gcloud config get-value project)/${SERVICE_NAME}:v1 -f bigquery/${SERVICE_NAME}/csharp/Dockerfile . docker push gcr.io/$(gcloud config get-value project)/${SERVICE_NAME}:v1
Deploy the container image to Cloud Run, passing in
PROJECT_ID
andTOPIC_QUERY_COMPLETED
:gcloud run deploy ${SERVICE_NAME} \ --image gcr.io/$(gcloud config get-value project)/${SERVICE_NAME}:v1 \ --update-env-vars PROJECT_ID=$(gcloud config get-value project),TOPIC_ID=${TOPIC_QUERY_COMPLETED} \ --allow-unauthenticated
When you see the service URL, the deployment is complete.
Create a trigger for the Query Runner service
The Eventarc trigger for the Query Runner service deployed on Cloud Run filters for messages published to a Pub/Sub topic.
Create the trigger:
gcloud eventarc triggers create trigger-${SERVICE_NAME} \ --destination-run-service=${SERVICE_NAME} \ --destination-run-region=${REGION} \ --event-filters="type=google.cloud.pubsub.topic.v1.messagePublished"
This creates a trigger called
trigger-query-runner
.Set an environment variable for the Pub/Sub topic.
export TOPIC_QUERY_SCHEDULED=$(gcloud eventarc triggers describe trigger-${SERVICE_NAME} --format='value(transport.pubsub.topic)')
Schedule the jobs
The processing pipeline is triggered by two Cloud Scheduler jobs.
Create an App Engine app which is required by Cloud Scheduler and specify an appropriate location:
export APP_ENGINE_LOCATION=LOCATION gcloud app create --region=${APP_ENGINE_LOCATION}
Create two Cloud Scheduler jobs that publish to a Pub/Sub topic once per day:
gcloud scheduler jobs create pubsub cre-scheduler-uk \ --schedule="0 16 * * *" \ --topic=${TOPIC_QUERY_SCHEDULED} \ --message-body="United Kingdom"
gcloud scheduler jobs create pubsub cre-scheduler-cy \ --schedule="0 17 * * *" \ --topic=${TOPIC_QUERY_SCHEDULED} \ --message-body="Cyprus"
The schedule is specified in unix-cron format. For example,
0 16 * * *
means that the jobs runs at 16:00 (4 PM) UTC every day.
Run the pipeline
First, confirm that all the triggers were successfully created:
gcloud eventarc triggers list
The output should be similar to the following:
NAME TYPE DESTINATION_RUN_SERVICE DESTINATION_RUN_PATH ACTIVE trigger-chart-creator google.cloud.pubsub.topic.v1.messagePublished chart-creator Yes trigger-notifier google.cloud.audit.log.v1.written notifier Yes trigger-query-runner google.cloud.pubsub.topic.v1.messagePublished query-runner Yes
Retrieve the Cloud Scheduler job IDs:
gcloud scheduler jobs list
The output should be similar to the following:
ID LOCATION SCHEDULE (TZ) TARGET_TYPE STATE cre-scheduler-cy us-central1 0 17 * * * (Etc/UTC) Pub/Sub ENABLED cre-scheduler-uk us-central1 0 16 * * * (Etc/UTC) Pub/Sub ENABLED
Although the jobs are scheduled to run daily at 4 and 5 PM, you can also run the Cloud Scheduler jobs manually:
gcloud scheduler jobs run cre-scheduler-cy gcloud scheduler jobs run cre-scheduler-uk
After a few minutes, confirm that there are two charts in the Cloud Storage bucket:
gsutil ls gs://${BUCKET}
The output should be similar to the following:
gs://BUCKET/chart-cyprus.png gs://BUCKET/chart-unitedkingdom.png
Congratulations! You should also receive two emails with links to the charts.
Clean up
If you created a new project for this tutorial, delete the project. If you used an existing project and wish to keep it without the changes added in this tutorial, delete the resources created for the tutorial.
Delete the project
The easiest way to eliminate billing is to delete the project that you created for the tutorial.
To delete the project:
- In the Google Cloud console, go to the Manage resources page.
- In the project list, select the project that you want to delete, and then click Delete.
- In the dialog, type the project ID, and then click Shut down to delete the project.
Delete tutorial resources
Delete the Cloud Run service you deployed in this tutorial:
gcloud run services delete SERVICE_NAME
Where
SERVICE_NAME
is your chosen service name.You can also delete Cloud Run services from the Google Cloud console.
Remove any gcloud CLI default configurations you added during the tutorial setup.
For example:
gcloud config unset run/region
or
gcloud config unset project
Delete other Google Cloud resources created in this tutorial:
- Delete the Eventarc trigger:
gcloud eventarc triggers delete TRIGGER_NAME
ReplaceTRIGGER_NAME
with the name of your trigger.
- Delete the container image
named
gcr.io/PROJECT_ID/SERVICE_NAME
from Container Registry.
- Delete the Eventarc trigger: